Hearing loss can happen at any age. However, hearing impairment at birth, or that develops in infants and toddlers, is of extra concern. It can lead to developmental challenges if not recognized and treated early, since normal hearing is needed to understand spoken language—and then, later, to produce clear speech.
If your child experiences hearing impairment during infancy and early childhood, immediate attention is needed. Even a temporary but significant hearing impairment during this time can make it very challenging for the child to learn spoken language or speech patterns.
Causes of hearing impairment in children
Most children experience mild hearing loss when fluid builds up in the middle ear from congestion, colds, or ear infections. This hearing loss is usually only temporary; normal hearing commonly returns once the congestion or infection gets better and the Eustachian tube (which connects the middle ear to the throat) drains the remaining fluid into the back of the throat.
In many children, perhaps 1 in 10, fluid stays in the middle ear following an ear infection because of problems with the Eustachian tube. Children with this problem don't hear as well as children typically do. Because of this, they sometimes have delays in talking.
Much less common is the permanent kind of hearing impairment that always impacts normal speech and language development. Permanent hearing impairment varies from mild or partial to complete or total.
Types of hearing or impairment
Conductive hearing loss
When a child has a conductive hearing impairment, there may be an abnormality in the structure of the outer ear canal or middle ear. Or, there may be a large amount of cerumen (wax) lodged in the ear canal. Another possible cause is fluid in the middle ear that interferes with the transfer of sound.
Sensorineural hearing loss (also called nerve deafness)
This type of hearing impairment is caused by an abnormality of the inner ear or the nerves that carry sound messages from the inner ear to the brain. The impairment can be present at birth or occur anytime after. Even without a family history of deafness, the cause is frequently genetic) Parents and other family members often are unaffected because each parent is only a carrier for a hearing-loss gene.
Or, if the mother had rubella (German measles), cytomegalovirus (CMV), toxoplasmosis, or another infectious illness that affects the inner ear during pregnancy, the fetus could have been infected and may lose hearing as a result. The impairment also may be from a malformation of the inner ear.
Signs of hearing impairment to watch for
Contact your pediatrician if:
Your child doesn't startle at loud noises by one month or turn to the source of a sound by three to four months of age.
They don't notice you until they see you.
They concentrate on gargling and other vibrating noises that they can feel, rather than experimenting with a wide variety of vowel sounds and consonants.
Their speech is delayed or hard to understand, or they don't say single words such as "dada" or "mama" by 12 to 15 months of age.
They do not say five to 10 words by 18 months of age.
They do not put two to three words together at two years of age.
Their speech is not understandable 50 percent of the time by two and a half years of age.
They don't always respond when called. (This is usually mistaken for inattention or resistance, but could be the result of a partial hearing impairment.)
They seem to hear some sounds but not others. (Some hearing impairment affects only high-pitched sounds; some children have hearing loss in only one ear.)
They seem not only to hear poorly but also has trouble holding their head steady, or is slow to sit or walk unsupported. (In some children with sensorineural hearing impairment, the part of the inner ear that provides information about balance and movement of the head is also damaged.)
Early diagnosis is key
Hearing impairment must be diagnosed as soon as possible, so that your child isn't delayed in learning language—a process that begins the day they are born. That's why, before baby goes home from the hospital after birth, they undergo a formal newborn hearing screening. However, at any time during your child's life, if you or your pediatrician suspect that they have a hearing impairment, insist that a formal hearing evaluation be performed promptly. Some family doctors, pediatricians, and well-baby clinics can test for hearing loss or fluid in the middle ear. If an impairment is detected, your child may be referred to an audiologist (hearing specialist), and/or an ear, nose, and throat (ENT) doctor (otolaryngologist).
Types of hearing exams for children
Auditory brainstem & otoacoustic emissions tests
If your child is under six months old, is unable to cooperate with or understand a hearing exam, or has significant developmental delays, they may be given one of two available tests. These are similar to the tests performed during newborn hearing screenings. They are painless and can take anywhere from five minutes to an hour.
The auditory brainstem response (ABR) test measures how the brain responds to sound during deep sleep. Clicks or tones are played into the baby's ears through soft earphones, and electrodes placed on the baby's head measure the brain's response. ABRs are performed during natural sleep in infants under three or four months old. Older babies and toddlers need to be sedated to undergo an ABR.
otoacoustic emissions test measures sound waves produced by the ear. A tiny probe is placed just inside the baby's ear canal, which then measures the response when clicks or tones are played into the baby's ear. Babies and young children usually do not need to be napping or sedated for this brief screening exam. It can be done at any age.
- Behavioral audiometry, or conditioned response audiometry, can be performed with a cooperative baby as young as six months old. This test uses a combination of visual and auditory stimuli. It can determine frequency-specific (although not ear-specific) hearing levels in infants and toddlers.
- Formal behavioral audiometry can determine hearing levels as well as eardrum function in each ear. This is performed using soft earphones that send sounds and words to the ear. It is typically well tolerated by children in the three- to five-year age range.
If these tests find that your baby may have a hearing impairment, a more thorough hearing evaluation should be done as soon as possible to confirm the diagnosis. Even mild hearing loss can affect overall hearing and should be properly diagnosed and treated.
Treatment for hearing impairment
Treating a hearing impairment will depend on its cause. If it is a mild conductive hearing caused by fluid in the middle ear, the doctor may simply recommend that your child be retested in a few months to see whether the fluid has cleared by itself. Medication such as antihistamines, decongestants, or antibiotics, are ineffective in clearing up middle ear fluid.
If there is no improvement in hearing over a three-month period, and there is still fluid behind the eardrum, the doctor may recommend referral to an ENT specialist. If the fluid persists and there is sufficient (even though temporary) conductive hearing impairment from the fluid, the specialist may recommend draining the fluid through ventilating tubes. These are surgically inserted through the eardrum. This is a minor operation and takes about 15 minutes, but your child must receive a general anesthetic for it to be done properly.
Even with the tubes in place, future infections can occur. But the tubes help reduce the amount of fluid and decrease your child's risk of repeated infection. If the cause for the hearing loss was purely the fluid, they will also improve hearing.
If a conductive hearing loss is due to a malformation of the outer or middle ear, a hearing aid may restore hearing to normal or near-normal levels. However, a hearing aid will work only when it's being worn. You must make sure it is on and functioning at all times, particularly in a very young child. Reconstructive surgery may be considered when the child is older.
Early placement of hearing aids for infants with hearing impairment is important to give them awareness of sound and language. Early exposure to either spoken or visual (sign) language has a very positive impact on language development. In children with mild to moderate sensorineural hearing impairment, hearing aids can improve hearing so much that most can develop normal speech and spoken language.
If your child has severe or profound hearing impairment in both ears and gets little or no benefit from hearing aids, they could be a candidate for cochlear implants. If your family is considering an implant for a child whose hearing loss occurred at birth, the best chances to develop useful speech and hearing come with getting the implants early (ideally by one year of age) rather than late (over three years old).
Most children with typical development who get cochlear implants early, along with intensive therapy after the surgery, can develop good to excellent hearing and can be supported in a mainstream educational setting. In addition, almost all children with cochlear implants gain better awareness of sounds in their environment.
Learning to communicate
Parents of children with sensorineural hearing loss usually are most concerned about whether their child will learn to talk. The answer is that although optimally timed cochlear implantation will greatly improve the chances of learning spoken language, not all may learn to speak clearly. However, all children with a hearing loss can be taught to communicate. Some children learn to lipread well, while others never fully master the skill.
Beyond spoken language
Keep in mind that speech is only one form of communication. For children who didn't get enough improvement from hearing aids or cochlear implants to develop spoken language, or for those families who have chosen not to pursue it, sign language is another type of communication that can be learned. If your child is learning sign language, you and your immediate family also must learn it. This way you will be able to teach, praise, comfort, and laugh with them. Encourage friends and relatives to learn signing, too. Written language is very important as well, because it is the key to educational and future career success.